Missing E-mail history in ACT!

I send an e-mail to someone on my contact list in Act, by clicking on his e-mail address in the e-mail field. The e-mail goes out and a history is created - the e-mail is attached to the contact. In "preferences- e-mail" - I had set it to attach e-mails to contact. So all is fine. That is until the next stage.

Say the person I just sent the e-mail to replies to me, or someone, who is in my Contact dB, sends me an e-mail and I in turn click "Reply". In the new e-mail window that opens, all seems well, the person's e-mail address is in the "To" field, exactly as it appears in the e-mail field in the Contact window in Act. So I reply and send the e-mail. However, no history is created in that contact's details in Act. The only history created is in My contact in Act, as if Act hadn't a clue who's e-mail address it was sending the e-mail to.

The only way I have found to overcome this, is if I overtype the person's contact name in the e-mail "To" field and Act seems to be able to resolve the connection between the contact and the e-mail address in that scenario. However, I frequently forget to do this overtyping bit.

Is this just a clunky feature in Act or am I missing something very obvious, here?